There's however a small feature in xmltodict that most people overlook: the streaming mode. I actually wrote xmltodict the day I tried to parse a Wikipedia dump, I just couldn't keep it all in memory but needed something more high-level than SAX.
xmltodict is in no way trying to compete with LXML feature-wise (no support for namespaces yet, just to name one thing). It's just a lightweight approach to roundtrip between XML and JSON documents that worked for my use case and decided to share it.